A Present invention relates to U.S. patent application Ser. No. 09/162,989 entitled, "Progressively-Formed Threaded Insert," now U.S. Pat. No. 5,927,920, which was filed on Sep. 30, 1998 and commonly assigned to the present Applicant. That patent application describes a product and method for progressively forming a threaded insert from die stamping and folding a sheetmetal blank. The entirety of said patent application is hereby incorporated by reference, as though fully set forth herein.
A shortcoming of this design, however, is the lack of a flange around the mouth of the insert. Inserts commonly include a flange, which may provide several important functions. For example, a flange at one end of an insert permits the insert to be orientable when used in combination with an automated feed system. Another advantage is that the flange provides a better lead-in for a first engagement thread since it provides a tapered opening around the mouth of the insert. In addition, the flange may provide an important electrical ground contact if the insert is used with a metallically coated substrate. Other advantages of a flange are that it provides a stop to ensure proper insertion depth and also provides a restriction for the material around the outside of the insert as it is installed when it is inserted into flowable material such as plastic. And finally, a flange provides a better appearance of the installed insert. Even though a flange provides all of these advantages, a fully circular flange is impossible to create with the method of forming an insert as described in the above-referenced U.S. patent application, Ser. No. 09/162,989.
Patent prior art of which the Applicant is aware and which is cited in the above-captioned patent application to Swanstrom includes U.S. Pat. No. 3,433,119 issued to Ballantyne et al on Mar. 18, 1969. This reference discloses a longitudinal sheet metal insert with internal and external punched-out barbs for insertion into a plastic material prior to receiving a threaded member. U.S. Pat. No. 3,496,800 discloses a triangularly-shaped sleeve which is internally threaded by pressing a tubular member against an internally-positioned threaded die. U.S. Pat. No. 3,314,509 issued to Olson on Mar. 23, 1943 discloses the use of a longitudinally-folded sheet metal fastener having interrupted threads, which are embossed into the sheet metal. U.S. Pat. No. 3,006,231 issued to Kahn on Oct. 31, 1961 discloses an internally threaded nut formed from longitudinally folded sheet metal where the threads are preformed on the sheet. U.S. Pat. No. 3,532,323 issued to Uhen on Oct. 6, 1970 discloses a laterally folded sheet metal nut having slots cut into the sheet, which receive and engage the external threads of a bolt. U.S. Pat. No. 5,419,043 issued to Laue on May 30, 1995 discloses a longitudinally folded fastener with thread indentations that utilizes an alignment tab. U.S. Pat. No. 1,111,749 issued to C. Joseph on Sep. 29, 1914 discloses a sheet metal insert, longitudinally folded, which employs outward-facing barbs and thread-engaging cutouts. U.S. Pat. No. 4,430,033 issued to McKewan on Feb. 7, 1984 discloses a sheet metal insert for foam plastic, which includes an outward-facing rippled surface and interfacing thread-engaging ribs.
However, none of the above teachings suggest the use of forming an internally threaded insert by progressive impact stamping of sheet material and then folding the stamped sheet to provide a flanged insert. The use of this method of fastener formation permits economies of manufacture, which are heretofore unattainable by any of the known prior art processes for forming threaded inserts.